Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268122AbUIKHUh (ORCPT ); Sat, 11 Sep 2004 03:20:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268129AbUIKHUh (ORCPT ); Sat, 11 Sep 2004 03:20:37 -0400 Received: from witte.sonytel.be ([80.88.33.193]:9141 "EHLO witte.sonytel.be") by vger.kernel.org with ESMTP id S268122AbUIKHUX (ORCPT ); Sat, 11 Sep 2004 03:20:23 -0400 Date: Sat, 11 Sep 2004 09:19:54 +0200 (MEST) From: Geert Uytterhoeven To: Linux Fbdev development list cc: Benjamin Herrenschmidt , Linux Kernel list , Andrew Morton Subject: Re: [Linux-fbdev-devel] fbdev broken in current bk for PPC In-Reply-To: <200409101328.57431.adaplas@hotpop.com> Message-ID: References: <1094783022.2667.106.camel@gaston> <200409101328.57431.adaplas@hotpop.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2407 Lines: 55 On Fri, 10 Sep 2004, Antonino A. Daplas wrote: > On Friday 10 September 2004 10:23, Benjamin Herrenschmidt wrote: > > Recent changes upstream are breaking fbdev on pmacs. > > > > I haven't had time to go deep into that (but I suspect Linus sees it > > too on his own g5 unless he removed offb from his .config). > > > > From what I see, it seems that offb is kicking in by default, reserves > > the mmio regions, and then whatever chip driver loads can't access them. > > > > offb is supposed to be a "fallback" driver in case no fbdev is taking > > over, it should also be "forced" in with video=ofonly kernel command > > line. This logic has been broken. > > Actually, I was thinking about this problem with offb. I was planning on > adding video=offb:off support for offb, and then place offb at the very top > drivers Makefile (the reason why I placed it there, but forgot to add the > setup support for offb). So, without the 'off' option, offb becomes the > first driver that gets initialized by reason that it's at the top, and with > the 'off' option, it just exits initialization immediately, giving the other > drivers a chance to get through. This is not suitable, since for dual-headed machines, you may want to have one card driven by its native driver, and the other by offb (as fallback, because no driver exists yet). > The second method is not harder but will involve, again, changes to all > drivers. The only sane method I can think of is to change fb_get_options so > it returns an error if: > > a. "off" option is enabled > b. "ofonly" is enabled but only if name != "offb" > > If fb_get_options returns an error, drivers will not proceed with their > initialization. The second method is more compatible with the > previous setup semantics. Yes, looks better (except that it's less clean, but I'm afraid we can't fix that easily). Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/